The present invention relates to a light radiator for effectively diffusing and radiating light rays, which have been transmitted through an optical cable or the like outside of said optical conductor cable.
The present applicant has previously proposed various ways to focus solar rays or artificial light rays by use of lenses or the like, to guide the same into an optical conductor cable, and thereby to transmit them onto an optional desired place through the optical conductor cable. The solar rays or artificial light rays transmitted and emitted in such a way are employed for photo-synthesis and for use in illuminating or for other like purposes, for example, to promote the cultivation of plants.
However, in the case of utilizing the light energy for cultivating plants as mentioned above, the light rays transmitted through the optical conductor cable has directional characteristics. Supposing that the end portion of the optical conductor cable is cut off and the light rays are emitted therefrom, the radiation angle for the focused light rays is, in general, equal to approximately 46.degree.. That is quite a narrow field. In the case of utilizing the light energy as described above, it is impossible to perform a desirable amount of illumination by simply cutting off the end portion of the optical conductor cable and by letting the light rays emit therefrom.
Therefore, the present applicant has already proposed various kinds of light radiators capable of effectively diffusing the light rays which have been transmitted through an optical conductor cable and radiating the same for illumination over a desired area. The present invention was made forming a link in the chain thereof. In particular, the inventor aims at applying intensified light rays to a desired position of the plants by keeping the light source at a distance to the plants and by moving the light source back and forth in order to supply the light rays over a wider area.